A solvent tune: The crystallization solvent affects the temperature and light dependence of the valence tautomeric behaviour of a 1:1 Co–dioxolene compound, thus offering a new possibility of tuning its charge distribution (see figure). This approach paves the way for the development of molecular magnetic materials whose properties may be controlled by chemical means.

Three novel Zn(hfa) 2 ‚2H 2 O‚polyether adducts have been prepared through simple procedures with stoichiometric quantities of zinc hydroxide, Hhfa, and polyether. The products have been characterized by elemental analysis, X-ray single-crystal analysis, fast atom bombardment mass spectra, 1 H and 19 F NMR spectra, thermogravimetric (TG)-differential TG-differential scanning calorimetry (DSC) thermal measurements, and infrared transmittance spectroscopy. An attempt to obtain water-free adduct was unsuccessful even using excess polyethers. X-ray single-crystal data of the Zn(hfa) 2 ‚2H 2 O‚diglyme adduct show that the polyether does not coordinate to the metal center. Nevertheless, metrical data are indicative of bridging interactions involving the oxygen of one coordinated H 2 O molecule and the three oxygens of the diglyme. Very mild heating (37-51 °C) results in liquid compounds that, in turn, can easily be evaporated. Preliminary gas-phase Fourier transform-IR measurements in vacuo suggest that the anhydrous Zn(hfa) 2 ‚diglyme forms upon evaporation due to competing H 2 O and diglyme ancillary ligation. Deposition experiments, in a low-pressure horizontal hot-wall reactor, on fused SiO 2 (quartz) substrates, result in ZnO films. X-ray diffraction measurements provide evidence that they consist of hexagonal ( 002) and (10l) oriented, crystals. UV-vis spectra show that the transmittance of as deposited films in the visible region is about 90%.

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The Cd(C 5 F 6 HO 2 ) 2 ‚2H 2 O complex was investigated by X-ray crystallography, mass spectroscopy, 1 H NMR spectroscopy, TG-DTG thermal measurements, and infrared transmittance spectroscopy. X-ray single-crystal data show that the cadmium ion is chelated by the oxygens of the hfa anion ligand and bound to the oxygens of two cis-disposed water molecules. Deposition experiments, in a low-pressure horizontal hot-wall reactor, on optically transparent SiO 2 substrates using the above complex result in CdO films. XRD measurements provide evidence that these complexes consist of highly oriented cubic crystals. UV-vis spectra show that the transmittance of as-deposited films in the visible region is about 70%. The surface structure of the CdO films was investigated by XPS. Resistivity measurements of the CdO films suggest TCO properties.